73908-63-1Relevant articles and documents
Baylis-Hillman mechanism: A new interpretation in aprotic solvents
Price, Kristin E.,Broadwater, Steven J.,Jung, Hyun M.,McQuade, D. Tyler
, p. 147 - 150 (2005)
(Chemical Equation Presented) Using reaction rate data collected in aprotic solvents, we have determined that the Baylis-Hillman rate-determining step is second order in aldehyde and first order in DABCO and acrylate. On the basis of these data, we have p
A new interpretation of the Baylis-Hillman mechanism
Price, Kristin E.,Broadwater, Steven J.,Walker, Brian J.,McQuade, D. Tyler
, p. 3980 - 3987 (2007/10/03)
On the basis of reaction rate data, we have proposed a new mechanism for the Baylis-Hillman reaction involving the formation of a hemiacetal intermediate. We have determined that the rate-determining step is second order in aldehyde and first order in DAB
Reactive Intermediates from the Solvolysis of Mutagenic O-Alkyl N-Acetoxybenzohydroxamates
Bonin, Antonio M.,Glover, Stephen A.,Hammond, Gerard P.
, p. 1173 - 1180 (2007/10/02)
Mutagenic O-(para-substituted benzyl) N-acetoxybenzohydroxamates undergo acid-catalysed solvolysis in aqueous acetonitrile but three is a change in mechanism from AA11 to E1 on going from para electron-withdrawing substituents to para +M electron-donating groups.The former permit the formation of a discrete nitrenium ion intermediate whereas the latter promote a concerted elimination of a resonance stabilized benzyl carbocation.
Biosynthesis of the Antibiotic Obafluorin from D-Glucose and p-Aminophenylalanine in Pseudomonas fluorescens
Herbert, Richard B.,Knaggs, Andrew R.
, p. 103 - 108 (2007/10/02)
The separate units which are used to construct the antibiotic obafluorin 1 in Pseudomonas fluorescens are defined by the results of D-glucose incorporation.A key intermediate in the biosynthesis of 1 is established to be L-p-aminophenylalanine 8; L-phenylanaline and L-p-nitrophenylalanine are very poor precursors.Results similar to those for obafluorin are obtained for p-nitrophenylacetic acid 20 which along with derivative 4 and 2-(4-nitrophenyl)ethanol 21 are identified as new metabolites of P. fluorescens.Deuteriated samples of 20, 22 and 23 are notprecursors for obafluorin 1. -p-aminophenylalanine 18 is incorporated into 1 with complete loss of deuterium from C-2 but retention of the deuterium present in both diastereotopic positions on C-3.
Kinetics and Stereochemistry of Elimination of Nitrous Acid from 1-p-Nitrophenyl-2-nitroethyl Derivatives
Norris, Robert K.,Wright, Timothy A.
, p. 281 - 294 (2007/10/02)
The eliminations of nitrous acids from the compounds (1) and (6) are E2 processes, which proceed with a large primary kinetic isotope effect and with antiperiplanar stereochemistry.The rate of elimination of HNO2 fom (1) is intermediate between the rate o
Photoredox chemistry of nitrobenzyl alcohols in aqueous solution. Acid and base catalysis of reaction
Peter, Wan,Yates, Keith
, p. 2076 - 2086 (2007/10/02)
The photochemistry of several m- and p-nitrobenzyl alcohols (1-5) has been studied in aqueous solution.These compounds react via an intramolecular photoredox pathway to give reduced and oxidized moieties of the substituent groups.The reaction is an example of a new type of photoreaction of nitro-substituted aromatic derivates that is not observed in organic solvents, the presence of water being essential.This effect is exemplified by measuring the quantum efficiency as a function of molpercent water in aqoeous acetonitrile, methanol, and formaldehyde: the reaction efficiency decreases rapidly as water is depleted in the mixture.Catalytic efficts due to the hydronium and hydroxide ions were studied: the para derivatives exhibited hydroxide ion catalysis; the meta derivatives exhibited hydroniumn ion catalysis.Quantum yields, solvent isotop effects, and α-deuterium isotope effects are reported for the parent derivatives.
Comparative Study of Reactions of 2-Benzylisoquinolinium and 3,4-Dihydro-2-benzylisoquinolinium Salts with Carbon Disulfide in Two Base-Solvent Environments
Duncan, James A.,Bosse, Mark L.,Masnovi, John M.
, p. 3176 - 3181 (2007/10/02)
3,4-Dihydro-2-(p-nitrobenzyl)isoquinolinium bromide (9a) reacts with carbon disulfide in both aqueous hydroxide-dioxane and triethylamine-pyridine to afford the expected 5,6-dihydro-3-(p-nitrophenyl)thiazoloisoquinolinium-2-thiolate (12) and a new
